South Carolina has averaged 11 tornadoes each year since 1950. South Carolina ranks twenty-sixth in the United States in the number of tornado strikes, and eighteenth in the number of tornadoes per square mile. The most common type of tornado, the relatively weak and short-lived type, occurs between March and May. However, tornadoes can occur almost anywhere at anytime.
Tornadoes are nature’s most violent storms. Spawned from powerful thunderstorms, tornadoes can cause fatalities and devastate a neighborhood in seconds. A tornado appears as a rotating, funnel-shaped cloud that extends from a thunderstorm to the ground with whirling winds that can reach 300 miles per hour. Damage paths can be in excess of one mile wide and 50 miles long. Every state is at some risk from this hazard. Some tornadoes are clearly visible, while rain or nearby low-hanging clouds obscure others. Occasionally, tornadoes develop so rapidly that little, if any, advance warning is possible. Before a tornado hits, the wind may die down and the air may become very still. A cloud of debris can mark the location of a tornado even if a funnel is not visible. Tornadoes generally occur near the trailing edge of a thunderstorm. It is not uncommon to see clear, sunlit skies behind a tornado.
- Be alert to changing weather conditions.
- Listen to NOAA Weather Radio or to commercial radio or television newscasts for the latest information.
- Look for approaching storms.
- Look for the following danger signs:
- Dark, often greenish sky
- Large hail
- A large, dark, low-lying cloud (particularly if rotating)
- Loud roar, similar to a freight train
- If you see approaching storms or any of the danger signs, be prepared to take shelter immediately.
- If you are under a tornado warning, seek shelter immediately.
- Get indoors to a pre-designated shelter area such as a basement, storm cellar or the lowest building level. If there is no basement, go to the center of an interior room on the lowest level (closet, interior hallway) away from corners, windows, doors and outside walls.
- Shutter windows and outside doors.
- If in a vehicle, trailer or mobile home, get out immediately and go to the lowest floor of a sturdy, nearby building or storm shelter.
- If unable to get indoors, lie flat in a nearby ditch or depression and cover your head with your hands. Be aware of potential flooding and flying debris.
- Never try to outrun a tornado in your vehicle. Instead, leave the vehicle immediately for safe shelter.
- Use the telephone only for emergency calls.
- Avoid downed power lines and report them to your utility company.
- Stay out of damaged buildings.